ampere

The base unit of electric
current in the SI system. One ampere
(A), or amp, is defined as the constant current that, if maintained in two
straight parallel conductors of infinite length and negligible circular
cross-section, and placed 1 meter apart in
vacuum, would produce between these conductors a force of 2 × 10-7newton per meter. It is named after
the French physicist André Marie Ampère.